We’ve launched a free vector cmyk QR code service on our Pressero site. You can find it here: http://www.pressero.com/free-vector-cmyk-qr-code.htm.
The service will quickly generate PDF and EPS versions (vector) and a TIF version (300 dpi) using the CMYK color of your choice. It also has the ability to save the QR Code with a spot color, in case you are printing using a specific PMS color, for example.
You’ll note that the QR Code generator can be easily added to any other web page using the simple embed code included on the page. Feel free to add it to your site if you think it will be of some benefit to your customers.